Auburn Hills — A 43-year-old medical marijuana card holder was charged Thursday with violating state law by illegally growing plants in the back yard of his home and within 1,000 feet of an elementary school.

Mark Alan Rowe of Auburn Hills is charged with one count of manufacturing the controlled substance of marijuana in connection with a search warrant executed Wednesday at his home on Caroline Street. The offense is a felony punishable by up to four years in prison and a $20,000 fine.

Rowe, who was released on $10,000 personal bond, holds a valid Michigan Department of Community Health medical marijuana patient ID card.

Auburn Hills Lt. Casimir Miarka said police received a tip Tuesday that marijuana was being grown in Rowe’s back yard and officers confiscated 12 plants from the yard, which has a four-foot high chain link fence.

“If he had the plants growing inside his house and secure, we wouldn’t be having this conversation because he does have a card,” Miarka said. “But I don’t think out in the open qualifies under the law.”

Miarka said some plants were more than six feet tall.

Police said under Michigan Department of Community Health administration rules, a qualifying patient can keep 12 plants in an enclosed, locked facility, defined as a “closet, room, or other enclosed area equipped with locks or other security devices that permit access only by a registered primary caregiver or registered qualifying patient.”